What is the answer?

4. A machine that originally had an estimated useful life of 12 years, but after 4 complete years, it was decided that the original estimate of useful life should have been 9 years. At that point the remaining cost to be depreciated should be allocated over the remaining: A. 2 years B. 5 years C. 7 years D. 12 years E. 10 years 5. A company receives a 5%, 90-day note for $6,400. The total interest due upon the maturity date is: A. $320 B. $40.00 C. $80.00 D. $240 E. $87.50